Medical devices are available for application of biocompatible agents to tissue surfaces. Devices range in type from those designed simply to extrude material from a reservoir directly onto a surface, to those able to spray material onto a surface and then to activate the material to change it in some way, for example by exposing it to polymerizing light. Devices exist that are designed to apply two or more agents to a tissue surface that react with each other spontaneously, or upon the application of light, to change harden.
Examples of devices for delivery of one or more agents to a tissue surface can be found in U.S. Pat. No. 5,582,596 (Fukunaga, et al.), U.S. Pat. No. 5,665,067 (Linder, et al.), U.S. Pat. No. 5,749,968 (Melenson, et al.), and in International Patent Application Serial No. PCT/US99/21521 (International Patent Publication WO 00/15117; Pichon, et al.). The latter (WO 00/15117) describes a gas-powered spraying device that can be used for single or multi-part reactive medical polymer compositions. In use, one or more fluids are sprayed independently at a tissue surface by introducing the fluids into a medical gas. The fluids can be stored in reservoirs which are attachable to the device at inlet ports fluidly connectable to an outlet of the device at which the fluids can be independently introduced into flowing gas and thereby delivered to the tissue surface. Gas flow is provided at two flow levels, including a high level flow for active spraying of material onto the tissue surface, and a low level flow to remove drips from the outlet and prevent clogging, to improve device reliability. In one arrangement, the two fluids are separately applied to a single tissue surface area at which they react to harden, spontaneously or photochemically.
In the above and other systems, it is often important to apply two or more fluids independently, and in some cases sequentially, to a tissue surface. In many cases it is desirable to apply fluids evenly or unevenly, depending upon various conditions, and in variable ratios between fluids. Although the above and other systems are useful in many instances, there remains a need in the art for improved devices that are even more convenient and versatile for simple and rapid application of material to tissue surfaces under a variety of conditions, including a variety of tissue surface conditions.